Within the next 50 years a supernova will ignite in the Milky Way, according to a team of scientists at The Ohio State University, who report the odds are almost 100 percent that the cosmic event will be visible with infrared radiation-detecting telescopes.
The news has excited astronomers, who will be able to do something never done before: detect a supernova fast enough to witness what happens at the very beginning of a star's demise.
Supernovae are the brilliant end of a star's life, the moment where the energy fueling its core depletes, right before the dead star explodes and shoots most of its mass out into space.
"We see all these stars go supernova in other galaxies, and we don't fully understand how it happens. We think we know, we say we know, but that's not actually 100 percent true," said Christopher Kochanek, professor of astronomy at Ohio State and the Ohio Eminent Scholar in Observational Cosmology. "Today, technologies have advanced to the point that we can learn enormously more about supernovae if we can catch the next one in our galaxy and study it with all our available tools."
Kochanek and his colleagues are almost certain that a supernova will be observable in the next half century, however, there is only about a 20 percent chance of being able to see the cosmic spectacle from Earth with the naked eye. Odds could be as high as 50 percent for people in the Southern Hemisphere, but lessen as the latitude increases. In Columbus, Ohio, for instance, the odds are only 10 percent, the researchers said.
Still, being able to observe a supernova occurring within the Milky Way would unveil a wealth of information about the galactic event, and perhaps prove some conventional ideas about supernovae wrong.
"Every few days, we have the chance to observe supernovae happening outside of our galaxy," said Ohio State doctoral student Scott Adams. "But there's only so much you can learn from those, whereas a galactic supernova would show us so much more. Our neutrino detectors and gravitational wave detectors are only sensitive enough to take measurements inside our galaxy, where we believe that a supernova happens only once or twice a century."
Adams continued: "Despite the ease with which astronomers find supernovae occurring outside our galaxy, it wasn't obvious before that it would be possible to get complete observations of a supernova occurring within our galaxy. Soot dims the optical light from stars near the center of the galaxy by a factor of nearly a trillion by the time it gets to us. Fortunately, infrared light is not affected by this soot as much and is only dimmed by a factor of 20."
When a star goes supernova it releases nutrinos immediately after the explosion starts. Super-sensitive nutrino detectors on the ground, such as the Super-Kaminokande in Japan or a new gadolinium-infused neutrino detector known as EGADS, will issue alerts the moment they detect nutrinos, and scientists can calculate the direction the nutrinos are coming from and look to the sky.
"With only one or two happening a century, the chance of a Milky Way supernova is small, but it would be a tragedy to miss it, and this work is designed to improve the chances of being ready for the scientific event of a lifetime," said John Beacom, professor of physics and astronomy and director of the Center for Cosmology and Astro-Particle Physics at Ohio State.
The astronomer's research is published in the The Astrophysical Journal.